(Slides given below)
The subject Theory of Machines may be defined as that branch of
Engineering-science, which deals with the study of relative motion between the various parts of
a machine, and forces which act on them. The knowledge of this subject is very essential for
an engineer in designing the various parts of a machine.
Sub- Divisions of TOM
Kinematics: It deals with the relative motion between the various parts of the machines.
Dynamics: It deals with the forces and their effects while acting upon the machine parts in Motion.
Kinetics: It deals with the inertia forces which arise from the combined effect of the mass and motion of the machine parts.
Statics: It deals with the forces and their effects while the machine parts are at rest. The mass of the parts is assumed to be negligible.
DEFINITIONS RELATED TO TOM
Kinematic link each part of a machine, which moves relative to some other part, is known as a kinematic link.
A link may consist of several parts, which are rigidly fastened together so that they do not
move relative to another part. For example, in a reciprocating steam engine, piston, piston
rod and crosshead constitute one link; connecting rod with big and small end bearings
constitute a second link; crank, crankshaft, and flywheel a third link and the cylinder, engine
frame and main bearings a fourth link.
Kinematic pair: The two links of a machine, when in contact with each other, are said to form a pair. If the relative motion between them is completely or successfully constrained (i.e. in a definite direction), the pair is known as kinematic pair
A kinematic chain is an assembly of links in which the relative motions of the links are possible
and the motion of each relative to the other